Irregular Bedtimes Reduce Children’s Cognitive Performance

How much do children’s bedtimes really matter for how their brains develop?

To measure the effects of bedtimes on cognitive function, researchers followed 11,000 children from when they were 3-years old to the age of 7 (Kelly et al., 2013).

Parents were asked about their children’s bedtimes at 3, 5 and 7-years-old. At 7, the children were tested on their reading, maths and spatial abilities.

The study found that:

“…irregular bedtimes at 3 years of age were associated with lower scores in reading, maths, and spatial awareness in both boys and girls, suggesting that around the age of 3 could be a sensitive period for cognitive development.”

In other words, regular bedtimes are important for both boys and girls and the earlier these can be implemented, the better for cognitive performance. The suggestion is that irregular sleeping patterns adversely affect development and these may cause permanent damage:

“Sleep is crucial for the maintenance of homeostasis and brain plasticity, including processes to do with embedding new knowledge, memory and skills into developing neural assemblies”

While is true of for both boys and girls, the study found that irregular bedtimes may be particularly bad news for girls.

Although children from more disadvantaged backgrounds tend to have less regular bedtimes, this was taken into account in the statistical models built by researchers:

“It might be that inconsistent bedtimes are a reflection of chaotic family settings and it is this, rather than disrupted sleep that impacts on cognitive performance in children. However, we found that inconsistent bedtimes were linked to markers of cognitive performance independent of multiple markers of stressful family environments. Findings from elsewhere suggest that stressful family environments affect children’s functioning via effects on sleep.”